Cummins Inc. has introduced a new 350-hp diesel engine for motorhomes:
the ISB XT. The ISB XT combines industry-leading fuel economy and the
highest power-to-weight ratio in its class. XT refers to extra torque
for hill-climbing ability.
The ISB XT carries forward many of the proven components of its
predecessor, the 5.9-liter ISB, with the patented VG Turbo, a proven
cooled Exhaust Gas Recirculation (cooled-EGR) system and sophisticated
Interact System electronic engine controls.
Modifications for 2007 include a 13-percent increase in
displacement to 6.7 liters, an increase in horsepower to 350 hp and a
higher peak torque rating of 750 lb-ft — while maintaining the same
exterior dimensions as the previous model.
The patented VG Turbo has new electric actuation to improve
engine responsiveness at every rpm. It also provides extra braking
power, eliminating the need for installation and maintenance costs
associated with an aftermarket “add-on” brake. The extra driver control
is especially important on steep downgrades and when towing.
The ISB XT has an integrated package that includes Cummins
Particulate Filter to reduce particulate matter emissions by 90 percent
from current levels and a crankcase ventilation system to capture
crankcase gases and return them directly to the sump. All components are
covered under a comprehensive five-year, 100,000-mile (160,935 km)